Variation in fine scale recombination rate in temperature-evolved Drosophila melanogaster populations in response to selection.

Abstract

Meiotic recombination plays a critical evolutionary role in maintaining fitness in response to selective pressures due to changing environments. Variation in recombination rate has been observed amongst and between species and populations and within genomes across numerous taxa. Studies have demonstrated a link between changes in recombination rate and selection but the extent to which fine scale recombination rate varies between evolved populations during the evolutionary period in response to selection is under active research. Here we utilize a set of three temperature-evolved Drosophila melanogaster populations that were shown to have diverged in several phenotypes including recombination rate based on the temperature regime in which they evolved. Using whole genome sequencing data of these populations, we generated fine scale recombination maps of the three populations. We compare recombination rates and patterns among the three populations and show that they have diverged at fine scales but are conserved at broader scales. We further demonstrate a correlation between recombination rates and genomic variation in the three populations and observe variation in putative warm-spots between the populations with these enhanced areas and associated genes overlapping areas previously shown to have diverged in the three populations due to selection. These data support the existence of recombination modifiers in these populations which are subject to selection during evolutionary change.